1. Field of the Invention
This invention relates to the field of article inspection, and in particular to an inspection system for transparent and translucent containers such as bottles. Means are provided to comprehensively examine each successive bottle in a line of adjacent bottles along a moving conveyor, without stopping them, including examination of container rims, bases, energy absorption and sidewall characteristics, using video detectors and energy absorption comparison means.
2. Prior Art
Various inspection systems have been attempted in which a plurality of containers such as glass bottles moving along a conveyor are automatically examined and automatically sorted based upon characteristics discovered. Although certain steps and certain elements of inspection apparatus have become quite sophisticated, it is not readily possible to arrange an inspection system in a comprehensive manner such that inspection can proceed smoothly and continuously without deliberately or inadvertently stopping the line and interfering with production processes upstream. Many disclosures of devices of this type employ apparatus that are regularly disruptive of smooth flow. Examples of such disruptions may be, for example, devices that remove containers from a straight conveying path for inspection, kickers, rotators, separators and diversion elements that are prone to knock containers down, and inspection stations that require some or all of the containers to be stopped in place, for example to be rotated and/or examined from a plurality of unobstructed angles that require a large conveyor section.
Reference may be made to various disclosures of particular arrangements by which rim inspection, base inspection, absorption or side wall inspection are carried out. Pat. 4,454,542-Miyazawa discloses a video rim inspection technique. Patents 4,391,373-Wiggins and 4,213,042-Beach, et al, disclose rim inspection devices including photocell pairs. Patents 3,932,042-Faani, et al, Re28,984-Drinkuth, et al teach side wall inspection techniques. Pat. 4,121,103 and 3,225,191, both to Calhoun, teach absorption and base analysis devices. These patents illustrate high levels of sophistication in the individual inspection procedures, criteria and means for discriminating and sorting containers. They do not, however, provide a system by which a plurality of such high quality individual inspection techniques can be coordinated, simultaneously or sequentially carried out, and resulting sorting of containers accomplished without either the regular stoppage of conveyors, or requirements due to timing, bottle separation rquirements or the like that interfere with flow of a continuous line of immediately-adjacent containers in a production plant or the like.
According to the invention, the containers are processed in a continuous line, each container resting directly against or positioned very close to adjacent containers, and the entire line moving continuously at high speeds. The containers need not be spaced for inspection, means being provided to conduct the necessary steps while the containers remain adjacent and moving.
According to the invention, means are provided bridging a gap defined between endless belt conveyor sections supporting containers from underneath, the bridge section having container side support belts frictionally engaging container sidewalls, for carrying the containers through inspection steps requiring axial viewing and/or exposure of the containers. The containers remain in a continuously-moving line. In the side wall inspection area, a video inspection system characterized by precise synchronism between bottle position and data capture additionally includes a bottle turning mechanism at the inspection zone by which all the containers passing without interruption one against another through the side wall inspection zone are turned continuously as they move along this part of the conveyor. A stationary rail on one side is opposed by a driven belt on the other side, for example moving at twice the conveyor speed, thereby rolling the bottles at full speed as they move continuously without generation of gaps.
The image recorded during sidewall inspection preferably encompasses several bottles. The video inspection means can be operable to analyze and reject for any defect found, and preferably also associates together the areas of successive several-bottle images that refer to a given container as it advances through the inspection zone, being rolled along the rail.
A downstream diversion element uses the moving bottles to squeeze out containers to be diverted from the line, allowing containers arriving in a continuous line to be smoothly sorted. This is accomplished by at least one and preferably two container support star wheels and a movable obstruction that, together with means for stopping a non-diverted bottle, squeeze the diverted bottle into a side path along a tangent to the at least one star wheel.
The invention as so described is a comprehensive bottle inspection system that is capable of all the sophistication of image analysis possible, yet does not interfere with container production and processing, the containers remaining adjacent one another in a continuously moving line.